An Encouraging Trial of a Mesh-Covered Stent in Primary Percutaneous Coronary Intervention

Compared with other devices, a bare-metal stent with a mesh covering to trap potentially embolic material was associated with a higher rate of ST-segment resolution.

The proven benefits of primary percutaneous coronary intervention in acute myocardial infarction (MI) can be limited by suboptimal myocardial perfusion due to distal embolization. In a manufacturer-supported randomized trial, investigators tested an experimental bare-metal stent covered with a polyethylene terephthalate micronet mesh for trapping and excluding embolism-prone material to find out whether the device reduces ST-segment elevation better than commercially available stents (including both bare-metal and drug-eluting devices).

A total of 433 patients with ST-segment-elevation MI were randomized. The rate of device success was lower with the covered stent than with control stents (96% vs. 99%, P=0.03); covered-stent failures included stent dislodgement during attempted withdrawal after unsuccessful vessel passage in two patients. The rate of the primary endpoint — complete ST-segment resolution (70%) summed across all 12 leads — was higher in the covered-stent group than in the control-stent group (58% vs. 45%; P=0.008). The secondary endpoints of thrombolysis in MI grade-3 flow and ST-segment resolution in the single lead with the greatest elevation were also significantly improved with the covered stent. However, no significant difference was found between the groups in myocardial blush grade or clinical events, although mortality trended lower in the covered-stent group.

CITATION(S):

Stone GW et al. Prospective, randomized, multicenter evaluation of a polyethylene terephthalate micronet mesh–covered stent (MGuard) in ST-segment elevation myocardial infarction: The MASTER trial. J Am Coll Cardiol 2012 Nov 6; 60:1975.